Improve XLSX output

[mjherzog]

I want to suggest two changes to the XLSX output to make the data easier to use for analysis.

• Change the worksheet names:

• Discovered Packages => PACKAGES

• Discovered Dependencies => DEPENDENCIES

• Codebase Resource => RESOURCES
  We have been following a convention to capitalize worksheet names to make them easier to recognize vs workbook names.

• Add package_type field in the DEPENDENCIES worksheet to avoid more complex filtering by purl to get quick information about Dependency items when you have mixed types from a Scan.

[tdruez]

@JonoYang I've implemented the name changes in 2eb75e7

Could you address the following in the dependencies branch?

Add package_type field in the DEPENDENCIES worksheet to avoid more complex filtering by purl to get quick information about Dependency items when you have mixed types from a Scan.